Eli Pariser was born on December 17, 1980 in Lincolnville, Maine. The son of two 1960s antiwar activists who founded an alternative high school in Camden, Maine, Pariser graduated from Bard College at Simon’s Rock (in Western Massachusetts) at the age of 19.

An outspoken critic of globalization, Pariser more than once participated in anti-World Bank and anti-International Monetary Fund (IMF) demonstrations where he squared off against riot police. He decided to alter his approach, however, after chatting for a few hours with police in the aftermath of an April 2000, anti-IMF rally in Washington, DC. "All of a sudden," recalls Pariser, "I realized that the scripted confrontation of attacking and antagonizing them wasn't going to get us anywhere. It changed the way I was thinking, tactically."

From that point forward, Pariser became increasingly aware that Internet activism could reach a larger audience than street rallies. Thus he shifted his attention to creating websites where he could disseminate his political convictions and promote his agendas. Following the terrorist attacks of 9/11, for instance, Pariser established the website 9-11peace.org, which implored the U.S. government to exercise “moderation and restraint” in its dealings with al Qaeda. More than half a million people signed the anti-war petition on that site.

In November 2001, when the United States and its allies were contemplating the possibility of using military measures to topple Saddam Hussein's regime in Baghdad, MoveOn.org founders Joan Blades and Wes Boydhired Pariser as a consultant to guide their organization's efforts to discredit the notion of waging war against Iraq. Before long, Pariser merged his own website with that of MoveOn, and in November 2002 he rallied some 9,000 MoveOn members to descend upon 400 government offices across the U.S. to voice their anti-war sentiments to members of Congress. Pariser was also instrumental in raising more than $400,000 for anti-war advertising.

In early 2002 Pariser worked directly with former Vice President Al Gore on drafting MoveOn-sponsored speeches, and in February 2003 Pariser spoke at a massive anti-war rally in New York City.

In December 2003 Pariser collaborated with Jonathan Soros, son of billionaire financier George Soros, and the techno-rocker Moby to organize “Bush in 30 Seconds,” an online contest for the best half-minute, anti-President Bush television advertisement. Among the 1,500-odd submissions were two ads juxtaposing footage of George W. Bush and Adolf Hitler, and MoveOn posted these on its website. Ultimately, under pressure from Jewish groups and Republicans, the organization pulled the Bush-Hitler ads and apologized for them.

In 2004 Pariser became executive director of MoveOn. That same year, he helped arrange some 1,000 neighborhood bake sales across the United States which raised at least $750,000 for the John Kerry presidential campaign.

On December 9, 2004 -- a month after Kerry's Election Day defeat -- Pariser declared that MoveOn had effectively taken control of the Democratic Party. “For years,” he said, “the party has been led by elite Washington insiders who are closer to corporate lobbyists than they are to the Democratic base. But we can't afford four more years of leadership by a consulting class of professional election losers.… In the last year, grass-roots contributors like us gave more than $300 million to the Kerry campaign and the DNC, and proved that the party doesn't need corporate cash to be competitive. Now it's our party: we bought it, we own it, and we're going to take it back.”

One of Pariser's top priorities has been to enlist young activists who can be groomed as leftwing leaders of the future. In an e-mail distributed to MoveOn members on November 22, 2005, for example, Pariser announced that his group (with the help of Zack Exley) had created a spinoff entity called the New Organizing Institute, a “grassroots program that trains young, technology-enabled political organizers to work for progressive campaigns and organizations.”

Pariser ended his tenure as MoveOn's executive director in 2008. Since then, he has been its board president.

In addition to his work with MoveOn, Pariser has served as the co-founder and board chairman of Avaaz.org, a board member of the Campaign for America's Future, an advisory council member for J Street, and an advisory board member for Res Publica. In March 2012 he co-founded Upworthy.com, a website whose mission is “to help people find important content that is as fun to share as a FAIL video of some idiot surfing off his roof.” In addition, Pariser is currently an advisor with State.com, a website that “allows people to express opinions in a quick and fun way [and] also provides enough information to interpret, count, and connect them.”